Morphometric Parameters of Krumbein Grain Shape Charts—A Critical Approach in Light of the Automatic Grain Shape Image Analysis

Grain-shape analyses are essential in geological research because they provide the basis for genetic interpretations, including sedimentation conditions. The methods of visual evaluation used so far have been subjective, time-consuming and labour intensive. Automatic particle image analysis, including the methods used by the Morphology G3SE device, open up the possibility of mass and objective roundness analysis of mineral and organic particles. The article presents the results of measurements for the grain scale proposed by Krumbein in 1941, as this scale has been used in numerous sedimentological studies. The standard shapes were analysed using four parameters: High Sensitivity (HS) Circularity, Convexity, Solidity and Aspect Ratio. In the discussion, both the results and the grain-shape standards were critically assessed. The most important trends in the distribution of morphometric parameters of the scale are shown. On this basis, it was found that it is impossible to determine the parameter boundary values that would distinguish each class of grain roundness proposed by Krumbein. The conclusions propose criteria for the automatic differentiation of angular, subrounded and rounded grains, which could be a basis for describing the shape of mineral particles.

Sexing white 2D footprints using convolutional neural networks

Footprints are left, or obtained, in a variety of scenarios from crime scenes to anthropological investigations. Determining the sex of a footprint can be useful in screening such impressions and attempts have been made to do so using single or multi landmark distances, shape analyses and via the density of friction ridges. Here we explore the relative importance of different components in sexing two-dimensional foot impressions namely, size, shape and texture. We use a machine learning approach and compare this to more traditional methods of discrimination. Two datasets are used, a pilot data set collected from students at Bournemouth University (N = 196) and a larger data set collected by podiatrists at Sheffield NHS Teaching Hospital (N = 2677). Our convolutional neural network can sex a footprint with accuracy of around 90% on a test set of N = 267 footprint images using all image components, which is better than an expert can achieve. However, the quality of the impressions impacts on this success rate, but the results are promising and in time it may be possible to create an automated screening algorithm in which practitioners of whatever sort (medical or forensic) can obtain a first order sexing of a two-dimensional footprint.

Luminescence properties of [Ir(C^N)2(N^N)]+ complexes: relations between DFT computation results and emission band-shape analysis data

For two series of [Ir(C^N)2(N^N)]+ luminophores, the computed DFT quantities remain in nice agreement with those available from the emission band-shape analyses.

Comparative 2D-shape analyses of collared lemmings in the zone of possible sympatry between Dicrostonyx groenlandicus and Dicrostonyx richardsoni (Rodentia, Arvicolinae)

Morphological differentiation and relationships among collared lemmings (Dicrostonyx Gloger, 1841) remain unclear. This issue is particularly important in the Kivalliq Region, Nunavut, Canada, where Dicrostonyx groenlandicus (Traill, 1823) and Dicrostonyx richardsoni Merriam, 1900 ranges overlap. Possible sympatry of both species obscures the taxonomic status of collared lemmings from this area. We compared 2D outline shapes of the skull and three upper molars of collared lemmings collected from seven areas of the Canadian Arctic, including specimens from the Baker Lake – Aberdeen Lake area, in the Kivalliq Region, and Dicrostonyx hudsonius (Pallas, 1778) as an outgroup. Multivariate analyses revealed two distinct groups when considering the molars: D. hudsonius, and the remainder of lemmings. Dicrostonyx richardsoni, D. groenlandicus, and the lemmings from the Baker Lake – Aberdeen Lake area showed significant differences, especially when considering skull shapes, thus suggesting three distinct groups. However, skull shapes proved inefficient in discriminating between species. These differences suggest that collared lemmings from the Baker Lake – Aberdeen Lake area may not be correctly assigned to either of the two species without further genetic evaluation. They also suggest that these lemmings should have a peculiar taxonomic status. Our study calls for further taxonomical investigations for collared lemmings from the overlapping distribution ranges of D. groenlandicus and D. richardsoni.

Comparison of Head Shape Outcomes in Metopic Synostosis Using Limited Strip Craniectomy and Open Vault Reconstruction Techniques

Aim: Metopic craniosynostosis (MCS), with its trigonocephalic head shape, is often treated with either limited incision strip craniectomy (LISC) followed by helmet orthotic treatment, or open cranial vault reconstruction techniques (OCVR). There is controversy regarding resultant shape outcomes among craniofacial surgeons. Those adverse to LISC claim normal head shape is never attained, while proponents believe there is gradual correction to an equivalent outcome. This study aims to quantitate, over time, the three-dimensional (3D) head shapes in patients who have undergone LISC or OCVR intervention for MCS. Methods: Sixty-three 3D images of 26 patients with MCS were analyzed retrospectively. Head shape analyses were performed at: (1) preoperative, (2) 1-month postoperative, (3) 10 to 14 months postoperative (1 year), and (4) 2 years postoperative. Composite 3D head shapes of patients were compared at each time point. Two-dimensional (2D) standardized cross sections of the forehead were also compared. Results: Composite head shapes for both groups were nested, to allow visual comparison as the child’s forehead grows and expands. The difference between LISC and OCVR 2D cross sections was calculated; 108.26 mm preoperatively, 127.18 mm after 1-month postoperative, 51.05 mm after 10 to 14 months postoperative, and 27.03 mm after 2 years postoperative. Conclusions: This study found excellent head shape outcomes for both the LISC and OCVR techniques at 2 years of age. It also corroborates the slow and progressive improvement in head shape with the LISC technique. This study highlights the advantages of 3D photography for measurement of contour outcomes, utilizing both 2D vector and 3D whole head analytical techniques.

Cone Beam Computed Tomography (Cbct) and Endodontic Microscopic Assessment of C-Shaped Canal Systems in Mandibular Second Molars

By knowing the anatomy of the tooth including root canal, dentists also have gathered physiologically anomalous requirements for effective root canal treatment. An exceptional morphology is present in the root canal system known as the C-shaped root network. A substantial volume of evidence already has come out on C-shaped root canal systems. The analysis provides an extensive description of root through root canals in the form of C. Characteristics of this exceptional morphology were studied mainly focused on macroscopic, microscopic and functional measurements including odontogenetic tooth shape analyses. To trying to clarify the clinical nature of C-shaped root canals, we sought to isolate them both. In addition to summarizing existing experiences, another of the objectives of this investigation was to find evidence that supports our interpretation of the C shaped root canal network. In fact, new advances in 3D mapping techniques help clarify the reliable etiology of the physiology of the Cshaped root canal network. Studies of extreme scenarios such as C-shaped root anatomy or morphology with rectangle and squared channels will also help us gain the wide range with root morphologies found in man’s teeth which eventually result in better care outcomes for patients and dentists and their satisfaction.